FOURTEEN

Emergent Animals II:

The March Towards the Veretebrates

adapted from Biology, 10th Edition, 2015, pp. 533, 625

PROKARYOTES

PROTISTS

EUKARYOTE

2200 mya (2.2 bya)

CHOANOFLAGELLATE ANCESTOR

THE FIRST ANIMAL!

(The Animal Kingdom)

unikont

bikont

(clade)

(clade)

(2 flagella)

opisthokont

bilateria

radiata

ctenophors - biradial symmetry

porifera (sponges): not true tissues

cnidaria - jellyfish, corals

placozoa

radial symmetry

2 clades

protostomes

deuterostomes

oral blastopore

spiral embryonic cleavage

branch

branch

lophotrochozoans

ecdysozoans

chordates

anal blastopore

echinoderms

hemichordates

radial embryonic cleavage

triploblastic

molluscs

annelids

platyhelminthes

single posterior flagellum

molting cuticle

hydrostatic, fluid-filled,

pseudo-coelom skeleton

nematodes (roundworms)

arthropods

urochordates

(tunicates)

cephalochordates

(lancelets)

VERTEBRATES

clade

clade

coelomates:

see definition 'coelom', below